From pirazoloquinolines to annulated azulene dyes: UV–VIS spectroscopy and quantum chemical study

Absorption and Fluorescence Spectra of Heterocyclic Isomers from Long-Range-Corrected Density Functional Theory in Polarizable Continuum Approach

“…The absorption bands are modeled here by the Gaussian function with the FWHM of 0.3 eV (DPIPQ) or 0.33 eV (PTNA), which most properly describes actual band shape broadening. Further methodology details regarding such calculations can be found in ref − and . The combined DFT/TDDFT/PCM/LC-BLYP calculations exhibit evidently better performance compared to the ones based on the hybrid xc-potential B3LYP.…”

“…Recent progress in the heterocycle organic chemistry has resulted in development of novel annulated analogues of azafluoranthenes and azulenes − representing the heterocyclic five- and seven-membered regioisomers, respectively. Similar organic materials were originally of interest for pharmacology, as efficient tissues oxygenators and antidepressant agents, , or biotechnology compounds used for binding of macromolecules, particularly as efficient DNA intercalators. , However, quite recent spectroscopic studies have revealed that such heterocyclic isomers may be also considered as novel efficient dyes for luminescent or electroluminescent applications in green-yellow region of the visible spectra. , The annulated azafluoranthene and azulene dyes were originally synthesized by Danel and co-workers from triphenylpyrazoloquinoline derivatives.…”

“…Similar organic materials were originally of interest for pharmacology, as efficient tissues oxygenators and antidepressant agents, , or biotechnology compounds used for binding of macromolecules, particularly as efficient DNA intercalators. , However, quite recent spectroscopic studies have revealed that such heterocyclic isomers may be also considered as novel efficient dyes for luminescent or electroluminescent applications in green-yellow region of the visible spectra. , The annulated azafluoranthene and azulene dyes were originally synthesized by Danel and co-workers from triphenylpyrazoloquinoline derivatives. Pirazoloquinolines itself are known as efficient fluorescent and electroluminescent materials preferably in blue, rarely blue-green regions of the visible spectra. − ,− Cyclization of triphenylpirazoloquinoline derivatives into the five or seven-membered heterocyclic regioisomers provides a significant red shift of the emission and first absorption bands that may be of interest for a number of applications. In the polar environment such dyes exhibit an opposite solvatochromism, i.e., the hypsochromic (blue) shift of the first absorption band and the bathochromic (red) shift of the fluorescence emission.…”

“…Pirazoloquinolines itself are known as efficient fluorescent and electroluminescent materials preferably in blue, rarely blue-green regions of the visible spectra. 4−6,30−32 Cyclization of triphenylpirazoloquinoline derivatives into the five or seven-membered heterocyclic regioisomers provides a significant red shift of the emission and first absorption bands 23 that may be of interest for a number of applications. In the polar environment such dyes exhibit an opposite solvatochromism, i.e., the hypsochromic (blue) shift of the first absorption band and the bathochromic (red) shift of the fluorescence emission.…”

Fluorescent and Phosphorescent Nitrogen-Containing Heterocycles and Crown Ethers: Biological and Pharmaceutical Applications

“…For example, fluorescent compounds known as quinolines have attracted the attention of scientists because of their use in high-tech applications [ 39 ]. Similarly, derivatives of the pyrazoloquinoline (PQ) family and quinoline are an example of fluorescent substances that may be of interest for several applications, including their use as oxidant scavengers and growth promoters [ 40 , 41 ]. These have also been found naturally in a wide range of foods and appear to be easily absorbed.…”